2π-space uniform-backscattering metasurfaces enabled with geometric phase and magnetic resonance in visible light

Abstract

Metasurfaces have shown unusual abilities to modulate the phase, amplitude and polarization of an incident lightwave with spatial resolution at the subwavelength scale. Here, we experimentally demonstrate a dielectric metasurface enabled with both geometric phase and magnetic resonance that scatters an incident light beam filling the full reflective 2π-space with high-uniformity. Specifically, by delicately reconfiguring the orientations of dielectric nanobricks acting as nano-half-waveplates in a metasurface, the optical power of phase-modulated output light is almost equally allocated to all diffraction orders filling the full reflection space. The measured beam non-uniformity in the full hemispheric space, defined as the relative standard deviation (RSD) of all scattered optical power, is only around 0.25. More interestingly, since the target intensity distribution in a uniform design is rotationally centrosymmetric, the diffraction results are identical under arbitrary polarization states, e.g., circularly polarized, linearly polarized or even unpolarized light, which brings great convenience in practical applications. The proposed uniform-backscattering metasurface enjoys the advantages including polarization insensitivity, high-integration-density and high-stability, which has great potential in sensing, lighting, laser ranging, free-space optical communication and so on.

Spectral imaging and spectral LIDAR systems: moving toward compact nanophotonics-based sensing

“…It works based on the scattering of light by the nanostructures. These nanostructures, also called as nanoantennas, can be patterned to achieve designed spectral response or phase profile, thereby enabling varied functional devices such as lenses [82,83], spectral filters [84,85], wave plates [86,87], beam deflectors [88][89][90] and point cloud generator [91]. For metalens, when the phase of the scattered light from nanoantennas follow the hyperboloidal profile below, the scattered light will focus at one point [81,82]:…”

Multi‐Dimensional Multiplexed Metasurface Holography by Inverse Design

“…[15,16] Benefiting from unprecedented control over electromagnetic waves at sub-wavelength scale, metasurface holography breaks these limitations and greatly expands the information capacity of traditional holography. [17][18][19][20][21][22][23] For example, polarization information can be loaded at different images to realize holographic encryption, [24][25][26][27][28] or to hide polarization-dependent holographic images, [23,29,30] vector color holographic metasurfaces can achieve color holography with arbitrary polarization distribution. [31][32][33] A long-employed approach to realize multi-dimensional multiplexed metasurface hologram is forward design, which often requires extensive physical knowledge for determining meta-atom arrangement strategies and hologram calculation algorithms.…”

Metasurface-driven full-space structured light for three-dimensional imaging

“…However, the largest scanning angle is limited to 15°. The metasurfaces projecting dots of light into diffraction angles close to 90°, giving a 180° FOV, have been demonstrated in the reflective and transmissive spaces 37 , 38 . The diffraction efficiencies to both reflective and transmissive spaces are same (27%) and were experimentally verified by a blazed grating and beam splitter.…”